Photographic film support having an antihalation layer

ABSTRACT

A PHOTOGRAPHIC FILM SUPPORT COMPRISING A FILM SUPPORT HAVING FORMED THEREON AN ANTIHALATION LAYER CONTAINING AT LEAST ONE MEMBER SELECTED FROM THE GROUP CONSISTING OF A HYDROXYALKYLALKYL CELLULOSE HEXAHYDROPHTHALATE AND A HYDROXYALKYLALKYL CELLULOSE TETRAHYDROPHTHALATE, WHEREIN SAID ALKYL GROUP HAS CARBON RANGE OF FROM 1 TO 4 CARBON ATOMS AND INCLUDES TWO OR MORRE ALKYL GROUP.

United States U.S. Cl. 11733.3 14 Claims ABSTRACT OF THE DISCLOSURE A photographic film support comprising a film support having formed thereon an antihalation layer containing at least one member selected from the group consisting of a hydroxyalkylalkyl cellulose hexahydrophthalate and a hydroxyalkylalkyl cellulose tetrahydrophthalate, wherein said alkyl group has a carbon range of from 1 to 4 carbon atoms and includes two or more alkyl groups.

BACKGROUND OF THE INVENTION Field of the invention The present invention relates to a photographic film support having an antihalation layer and more particularly, it relates to a photographic support having an antihalation layer which is excellent in stability to hydrolysis and can be completely removed by development processing.

Description of the prior art It has ordinarily been practiced in the art of producing photographic light-sensitive materials to provide a light-sensitive emulsion layer to one surface of a film support and an antihalation layer to the other surface (back surface) of said support. That is to say, by the presence of the antihalation layer, the light which is reflected to the light-sensitive emulsion layer and exhibiting a detrimental influence thereon is absorbed. The anithalation layer for such purpose is ordinarily composed of an antihalation material, such as carbon, graphite or a dyestulf that absorbs the greater part of the light in a wavelength region sensitive to the photographic film, and a binder. Illustrative of the binders are carboxylic acid-vinyl copolymers such as an acrylic acidacrylic acid ester copolymer, a maleic anhydride-styrene copolymer, and an acrylonitrile-maleic acid copolymer and cellulose acetate phthalate. However, because of the solubility of these binders in organic solvents, the unstability thereof caused by the presence of the acetyl group which is readily isolated, and the adhesive property thereof to gelatin layers, these binders are highly undesirable since they hamper formation of the antihalation layer. That is, the antihalation layer adheres to the sur face of the light-sensitive emulsion layer of the photographic film in a high humidity atmosphere and also exerts a detrimental influence on the photographic properties of emulsion layers of the light-sensitive film.

Thus, it is highly desirable to find an antihalation layer which does not spoil light-sensitive emulsion layers, does not decompose and contaminate a developing solution by being readily dissolved in the photographicalkaline developing solution, and is stable at a comparatively high humidity and temperature (stable to hydroylsis).

Therefore, the primary object of this invention is to provide a photographic film support having an antihalation layer which overcomes those disadvantages discussed above.

2 SUMMARY or THE INVENTION Accordingly, the present invention provides a photographic film support comprising a film support and an antihalation layer formed thereon, said antihalation layer containing an antihalation material and at least one mem ber selected from the group consisting of hydroxylkylalkylcellulose hexahydrophthalate and hydroxyalkylalkylcellulose tetrahydrophthalate, wherein the alkyl group has a carbon range of from 1 to 4 carbon atoms and incudes two or more alkyl groups.

DETAILED DESCRIPTION OF THE INVENTION In the instant invention, a hydroxyalkylalkylcellulose hexahydrophthalate or a hydroxyalkylalkylcellulose tetrahydrophthalate constitutes the binder. Accordingly, there are many compounds applicable by varying the hydroxyalkyl and alkyl moieties. For instance, there are hydroxypropylmethylcellulose hexahydrophthalate and hydroxypropylmethylcellulose tetrahydrophthalate.

The hydroxypropylmethylcellulose hexahydrophthalate illustrated above as one of the binders used in this invention may be produced by subjecting hydroxypropylmethylcellulose and hexahydrophthalic anhydride to an esterification reaction in a reaction medium, such as glacial acetic acid or propionic acid.

The proportions of the substituents of the hydroxyalkylalkylcellulose hexahydrophthalate and the hydroxyalkylalkylcellulose tetrahydrophthalate used in this invention as the binder are not particuarly limited but it is preferable for the purpose of this invention that the binders contain 1070% by weight of a hexahydrophthalyl group or a tetrahydrophthalyl group, 270% by weight of a hydroxyalkoxyl group and 2-35 by weight of an alkoxyl group. More preferably, they should contain 15- 45% by weight of a hexahydrophthalyl group or a tetrahydrophthalyl group, 3-60% by weight of a hydroxyalkoxy group, and 10-25% by weight of an alkoxyl group.

The solvent for the mixture of the hydroxyalkyl cellulose tetrahydrophthalate or the hydroxyalkylalkyl cellulose hexahydrophthalate and the material used for applying the antihalation composition to a film support is selected based on the properties of the film support to which the antihalation composition is to be applied. For example there are ketones, esters, alcohols, aromatics, and mixtures of them.

The antihalation composition used in this invention may be applied to various kinds of film supports, such as nitrocellulose films, triacetylcellulose films, acetylpropionyl cellulose films, polycarbonate films, and polyester films.

Illustrative of the antihalation materials used in this invention are carbon dispersions (colloidal carbons). Furthermore, dyestuffs absorbing light in a wavelength region sensitive to photographic films can also be used as the antihalation material in this invention. When using such dyestuffs, dyestutfs may be applied to a film support as a mixture with the hydroxyalkylalkyl cellulose hexahydrophthalate or hydroxyalkylalkycellulose tetrahydrophthalate and may be applied after the layer of the binder is first formed on the film support to the surface of the binder layer, whereby the dyestufi? is diffused into the binder layer in only the surface portion thereof. By the latter method, the dyestufl can be prevented from being transferred to the film support and hence the latter application is particularly profitable when such dyestuif exhibits a tendency of diffusing from one layer to the other.

As the antihalation dyestuffs used in this invention, there are illustrated Spirit Blue CR (Color Index No. 689), Nigrosine Spirit Soluble (Color Index No. 864, Alkali Blue B (Color Index No. 704), and Congo Red (Color Index No. 370).

The only necessary condition concerning the amount of the antihalation material is that the amount of the said material must be sufiicient for absorbing substantially the whole proportion of the light passed through the film base at light exposure of the photographic film.

The carbon dispersion employed as the antihalation material in this invention is preferably prepared by dispersing carbon powder in a mill of a type used for hot milling or coating mixing or in a homogenizer.

Also, the coating composition for the antihalation layer in this invention may contain a small amount of a filmforming agent such as ethylcellulose, shellac, gelatin, or hydroxypropyl cellulose or a coating aid, such as acetin. In particular, when a carboxylic acid-vinyl copolymer is used in the coating composition of this invention, an antihalation layer having excellent dull surface can be formed.

The present invention will be better understood from the following examples which are merely intended to be illustrative and not limitative of the present invention.

Example 1 Parts Hydroxypropylmethyl cellulose hexahydrophthalate (containing 38% by Weight of hexahydrophthalyl group, 8% of hydroxypropoxyl group, and 16% methoxyl group) Spirit Black (Color Index No. 50415) 5.3 Ethanol 600 Sodium salt of lauryl sulfonate 0.5

By applying the coating composition having the above composition to a triacetylcellulose film support and drying, an antihalation layer was formed.

The antihalation layer of the photographic film thus formed exhibited good resistance to the occurrence of photographic spots and adhesion in a high humidity. Also, when the antihalation layer was processed in an alkaline developing solution, it was readily removed from the film support.

Example 2 Parts Hydroxypropylmethyl cellulose hexahydrophthalate (same as used in Example 1) 20 Carbon black 9.6 Acetone 60G Methyl Cellosolve 150 Methanol 200 Diacetone alcohol 50 By applying the coating composition having the above composition to a triacetyl cellulose film support and drying, an antihalation layer was formed.

The antihalation layer of the photographic film thus formed had a hi h stability to hydrolysis and good solubility in an alkaline developing solution as in Example 1.

Example 3 An ordinary gelatino silver halide photographic emulsion was applied to one surface of a triacetyl cellulose film and then the coating composition having the following composition was applied to opposite surfaces of the film:

Parts Styrene-maleic anhydride copolymer (styrenezmaleic anhydride=l:1) 5.8 Acetone 65 Ethanol 250 Water 10 Thereafter, to the surface of the layer thus formed was applied the coating composition for the second layer having the following composition:

Parts Hydroxypropylmethyl cellulose hexahydrophthalate (as in Example 1) 15 Carbon black 9.2

Actone 420 Methyl Cellosolve 340 Ethyl alcohol 200 Sodium acetate 2 The antihalation layer of the photographic film thus obtained was stable under high-humidity and high-temperature conditions and could be readily removed by treating it with an alkaline developing solution.

Example 4 By following the same procedure of Example 1 using hydroxypropylhydroxybutylmethyl cellulose hexahydrophthalate (containing 25% by weight of hexahydrophthalyl group, 8% by weight of a hydroxypropyl group, 2% by weight of a hydroxybutyl group, and 18% by weight of a methoxyl group) in place of hydroxypropylmethyl cellulose hexahydrophthalate, an antihalation layer was formed. The layer showed good results as in Example 1.

Example 5 By following the same procedure of Example 2 using hydroxyethylmethyl cellulose hcxahydrophthalate (con taining 46% by weight of a hexahydrophthalyl group, 8% by weight of a hydroxyethoxyl group, and 15% by weight of a methoxyl group) in place of hydroxypropylmethyl cellulose hexahydrophthalate, an antihalation layer was formed. The antihalation layer thus formed exhibited good results as in Example 2.

Example 6 By following the same procedure as Example 2 using hydroxypropylethyl cellulose tetrahydrophthalate (containing 25% by Weight of a tetrahydrophthalyl group, 12% by weight of a hydroxypropyl group, and 15% by weight of an ethoxyl group) in place of hydroxypropylmethyl cellulose hexahydrophthalate, an antihalation layer was formed. The antihalation layer thus obtained exhibited excellent results as in Example 3.

Although the present invention has been adequately discussed and described in the foregoing specification and examples included therein, it is readily recognized that various changes and modifications may be made without departing from the scope and spirit thereof.

What is claimed is:

1. A photographic film support comprising a film support having formed thereon an antihalation layer containing an antihalation material and at least one member selected from the group consisting of a hydroxyalkylalkyl cellulose hexahydrophthalate and a hydroxyalkylalkyl cellulose tetrahydrophthalate, wherein said alkyl group has a carbon range of from 1 to 4 carbon atoms and includes two or more alkyl groups.

2. The photographic film support of claim 1, wherein said hydroxyalkylalkyl cellulose hexahydrophthalate is a member selected from the group consisting of hydroxypropylmethyl cellulose hexahydrophthalate, hydroxypropylhydroxybutylmethyl cellulose hexahydrophthalate, and hydroxyethylmethyl cellulose hexahydrophthalate.

3. The photographic film support of claim 1, wherein said hydroxyalkylalkyl cellulose tetrahydrophthalate is a member selected from the group consisting of hydroxypropylethyl cellulose tetrahydrophthalate and hydroxypropylmethyl cellulose tetrahydrophthalate.

4. The photographic film support of claim 1, wherein said antihalation material is a member selected from the group consisting of carbon black and a dyestulf capable of absorbing light in a wavelength region sensitive to the photographic film.

5. The photographic film support of claim 1, wherein said antihalation layer is formed directly on the film support.

6. The photographic film support of claim 1, wherein said antihalation layer is formed on the film support after precoating the support with a binder layer.

7. The photographic film support of claim 1, further containing a film-forming agent selected from the group consisting of ethyl cellulose, shellac, gelatin, and hydroxypropyl cellulose.

8. The photographic film support of claim 1, further containing as a coating aid, acetin.

9. The photographic film support of claim 1, wherein the hexaand tetra-hydrophthalyl group is present in an amount of 10-7 0% by weight.

10. The photographic film support of claim 1, wherein the hydroxyalkyl group is present in an amount of 2-70% by weight.

11. The photographic film support of claim 1, wherein the alkoxy group of said member is present in an amount of 235% by weight.

12. The photographic film support of claim 9, wherein said group is present in an amount of 15-45% by weight.

13. The photographic film support of claim 10, wherein said group is present in an amount of 360% by weight.

14. The photographic film support of claim 11, wherein said group is present in an amount of 1025% by weight.

References Cited UNITED STATES PATENTS 3,489,743 1/1970 Crane 96--84 3,392,022 7/1968 Gandy 9684 RONALD H. SMITH, Primary Examiner US. Cl. X.R. 96-84 R 

